Title: Probing and Manipulating Valleys in van der Waals Monolayers and Heterostructures
When: Monday, 10th September, 2018, at 12:00.
Place: Department of Condensed Matter Physics, Faculty of Sciences, Module 3, Seminar Room (5th Floor).
Speaker: Xiaoqin Li, Associate Professor of Physics, University of Texas-Austin, USA.
Valley pseudospin in atomically thin semiconductors has been proposed and pursued as an alternative information carrier to charge. I discuss a few examples of our recent work in this area (i) We directly measure quantum coherence between valley indexes associated with excitons and trions in transitional metal dichalcogenide (TMD) monolayers. (ii) We discover an exceptionally long valley polarization time associated with intra-valley excitons in Monolayer WSe2. (iii) We explore a method for separating valleys in real and momentum space using a metasurface. (iv) Finally, I will discuss our most recent studies on interlayer excitons confined in moiré potential of a TMD vertical heterostructures.
Xiaoqin Li received her B.S degree from Beijing Normal University in 1997 and PhD in physics in 2003 from University of Michigan. She was a postdoc fellow at JILA, Colorado from 2003-2006. She started as an assistant professor at UT-Austin in 2007 and was promoted to full professor in 2018. Prof. Li has received a number of awards including the Presidential Early Career Award for Scientists and Engineers in the U. S. and a Sloan Fellowship. She held a Humboldt Fellowship in 2015-2016 when she visited the Technical University of Berlin. She is a fellow of the American Physics Society.